BIT 1989 Volume 8 Issue 1

The paper first presents a discussion of non-linearities in human sequential
behaviour -- in terms of interleaving -- and then introduces the concepts which
underlie non-linear phonology. The paper does not provide a full treatment of
the theory of non-linear phonology, nor of its generalization to cover
non-speech activities -- these can be found elsewhere in the literature. The
significance of the formalism of non-linear phonology for researchers and
designers in human-computer interaction is revealed through the discussion of
several examples, ranging from general behaviour with a multi-tasking
interface, via interleaved activities in the use of a note-taking aid, to
programming itself.

Paralanguage and Human-Computer Interaction. Part 1: Identification of
Recorded Vocal Segregates

Vocal segregates are short non-lexical utterances such as 'mm-hmm'. They
are frequently observed in natural dialogue, which they help to regulate and
maintain. Twenty-five naive subjects were asked to identify the meanings of
isolated vocal segregates recorded by unfamiliar speakers. The segregates were
recorded both with natural articulation, which enables the differentiation of
vowel sounds, and with the speaker's mouth closed. Responses were made using a
seven-alternative forced choice procedure. Mean identification accuracy was
69.4% significantly above chance level, and performance was higher for vocal
segregates which contained vowel sounds. The possible role of vocal segregates
in human-computer interaction is discussed.

The comprehension of synthesized vocal segregates was studied using a
paired-associate learning task. Twenty-one naive subjects attempted to learn
associations between six vocal segregates and assigned meanings, where the
segregates were synthesized using the simple sound facilities common to all
PC-compatible machines. In the natural condition sounds were paired with the
correct meanings, whereas in the random condition sounds were randomly assigned
to incorrect meanings. Subjects in the natural condition showed a significant
initial advantage over those in the random condition and significantly better
overall performance across learning trials. The results show that uninformed
subjects are predisposed to make the correct sound-meaning associations for
segregates synthesized with inexpensive hardware, and that associations which
are not initially identified are quickly learned. Potential applications are
discussed.

Two experiments were carried out to find an optimal electronic text display
method given limited display space. The display formats tested fell into two
categories: Times Square, in which text is scrolled from right to left; and
rapid, serial, visual presentation (RSVP), in which text is presented one or
several words at a time to a fixed location in the display. Previous studies
have indicated that Times Square format is not as efficient as page format
display or, by extrapolation, as RSVP. These studies, unlike the present
experiments, did not include a smooth-scrolling (pixel-by-pixel) condition. In
Experiment 1, a comparison was made between multiple-word RSVP and three
versions of Times Square format, differing only in the size of steps by which
the display was scrolled. Except for the largest step-size, comprehension was
as high in the Times Square conditions as in the RSVP condition. The subjects
expressed a significant preference for smooth scrolling Times Square over any
other condition. Experiment 2 showed that comprehension for smooth scrolling
Times Square was at least as high as that for RSVP at presentation rates
ranging from 100 to 300 words per minute. Times Square reading is discussed in
terms of optokinetic nystagmus (OKN).

A number of indications which bear upon the utility of graphical
representations of data are presented. The indications are based upon the
apparent cognitive demands of particular forms of information abstraction. A
study is reported where hypotheses concerning the appropriateness of
alternative forms of graphical display for the presentation of particular
properties of data are tested. A large number of significant differences
between alternative forms of presentation in terms of effectiveness for
communicating major features of data are identified and discussed.

The costs of designing and producing electronic information products include
two important elements not often investigated: production time and worker
satisfaction. These aspects of preparation of videotex databases were examined
through interviews of industry professionals and a case study. Professional
designers and administrators were interviewed to estimate frame production
rates and to assess job satisfaction. In the case study, a team created a
database of 1273 frames. Average frame creation times were 7.2 min (text), and
10.1 min (text plus graphics). In both studies, job satisfaction came
principally from the challenge of working in a new medium. The results
suggest: (a) premonitory planning is essential for design and production; (b)
frame production depends upon several discrete task elements; and (c) the
tension between creativity and productivity is significant for those who
produce electronic information products.

A common criticism of authoring languages used for computer aided
instruction is that they are too restrictive. This article describes how one
command within the Proforma authoring language enables the user to leave the
confines of that language, run another program, and then return to the exact
spot within the original Proforma study unit at which it was left. Two systems
are outlined, one in which the separate program is accessed by chaining, and
another in which subprograms are used. An example of an application in French
language teaching is described in some detail.

BIT 1989 Volume 8 Issue 2

Performance measures are frequently used to evaluate user friendliness of a
system. An equally important, but often overlooked factor is the users'
attitudes towards a system. A prototype interface for information retrieval
was developed for presenting engineering manuals online. It was tested on a
representative sample of the intended end user community. We found that
subjects' expectations were based on their experience with printed materials
and other computer systems. Familiar search mechanisms (e.g., table of
contents, index) were important for getting them started, even though they
switched to other mechanisms as they gained more experience with the system.
The fact that the index was more detailed than the one in the printed manual
was seen by the subjects as critical for speedy and efficient information
retrieval. Keyword search of the database was generally the preferred
retrieval mechanism. However, some users preferred the index. The 'Table of
Contents' which was a tree structured menu based system was found to be of
limited use in the electronic medium, in contrast to the printed manual.

This article reviews three previous factor analysis based studies of
aggregate attitudes concerning the computer milieu and compares them with a
recent one done by the authors; the four studies span almost twenty years.
While providing a useful basis for making generalizations about current
perceptions of the computer's role, the latest study also sought to determine
whether there was a group of persons who were fearful or anxious about the
computer, whose concerns were masked in studies of aggregate attitudes. By
using an instrument that was evaluated by an expert in phobic behaviour, it was
possible to identify a population that was significantly different from the
general population in attitude towards computers. The value of the current
study, then, is two-fold. It makes possible a retrospective view of aggregate
perceptions of the general population about computers and also offers a glimpse
of the attributes of those computer phobic or anxious persons who have not yet
adapted to computer technology.

Social Meaning of Personal Computers for Managers and Professionals:
Methodology and Results

The social meaning of personal computers for 34 managers and professionals
was measured using a situational approach. The results, in general, indicated
a positive perception towards computers within the context of their work
situations. The methodology was developed in an attempt to overcome some of
the difficulties of traditional measures of attitudes. The advantages and the
limitations of the method, as well as the process by which impressions are
formed, are discussed.

The factors leading to the success or failure of IT implementations by
accountants are investigated in a health service situation. The case study
adopts the participant observation methodology and the factors observed are
classified as motivators and demotivators. Using a project dependent
definition of success, a catastrophe theory framework is used to describe the
outcome of the combined influence of these factors. Four particular IT
projects are discussed and the factors observed include: the influence of
higher levels in the organizational hierarchy, some systems characteristics,
the seduction of technology, external pressures, the 'rate of change', skills
shortage and reliability. By comparing the examples described with features
mentioned by other authors, it is noted that some factors appear to be
generally applicable, whereas others may be context dependent.

Menu selection in human/computer interaction is a metaphor of the restaurant
menu. Although menu selection is widely used, its scope is currently limited,
ill-defined, and information lean. A comparison of the restaurant menu and the
computer menu reveal three avenues of improvement in menu systems. The
correspondence of elements and features between restaurant and computer menus
suggests that this powerful metaphor should be more fully developed. Second,
there are a number of advantages of dynamic computer menus over static listings
common to restaurants. Finally, restaurant menus currently have the advantage
of breadth, richness, and graphic layout as well as a natural support system
(the server) that is unparalleled in current computer applications. An
analysis of deficiences in computer menus should prove invaluable in developing
the next generation of menu selection techniques.

The Effects of the Availability of Menu Information During Command Learning
in a Word Processing Application

An experiment is reported investigating the transition from relying on an
external memory aid for system commands, provided by a permanently visible
menu, to relying on internal memory for commands. Menu availability, and the
method of command entry (keyboard vs. mouse) were manipulated during the early
stages of learning the basic commands required to operate a word processing
application. It was found that a group which always had the benefit of a
memory aid provided by a menu performed no more efficiently than a group never
provided with a menu. A group initially provided with a menu, which was then
withdrawn performed significantly more slowly, and with more recourse to help
facilities than the later group. When the menu was permanently visible there
were no performance differences between the keyboard and mouse methods of
command entry. Implications of these findings for interface design are
discussed.

BIT 1989 Volume 8 Issue 3

Recent technological developments have stimulated the use of computer aided
manufacturing (CAM) machinery in industrial settings. Though managers
typically consider technical and economic factors in the implementation of CAM,
they rarely consider the psychological implications of work in CAM. Recent
research indicates that work in CAM may have unintended negative impacts on
worker well-being. This paper reviews and evaluates empirical research
concerning the impacts of work in CAM on worker well-being, and suggests
directions for future research in this area.

Allocating Functions in Computer Integrated Manufacturing: A Review and a
New Method

This paper describes the importance of allocating functions in advanced
manufacturing systems, both for the system and for the people. Existing
approachs to allocation are reviewed, along with some of their weaknesses. A
set of requirements of allocation methods is outlined, which if met would
promote their 'usability' for designers. As a result of collaborating in an
ESPRIT CIM project, a new method for function allocation is described and its
potential usability assessed.

There has been little empirical research on the human aspects of CAD
systems. In this paper observations on the analyses of designer activities are
presented, by using a systems design approach.
The paper concentrates on situation analysis and subsequent allocation of
system tasks. A situation analysis was carried out in two design departments.
The analysis consisted of a formal system description and a reconstruction
interview. During the interview the previous week's activities were
reconstructed with the help of photographs of the drawing board and protocols
completed by design draughtspersons. This procedure was used for six design
projects.
In this study the technique of the reconstruction interview proved to be
very useful and informative, and enabled three general conclusions to be made.
First, designers liked the initial design phase and their responsibility for
the final result. Second, they disliked the activities associated with drawing
as well as the project documentation phase. Third, they preferred to work with
two or more drawings on the drawing board. A number of frequent tasks could be
identified, for example, large scale manipulation within and between drawings.
In the final section, an example of a global allocation of system tasks for
the design of a CAD system is given.

Back to Thinking Mode: Diaries for the Management of Information Systems
Development Projects

From a practical point of view, systems development methods are important
sources of inspiration for the planning and establishment projects, but only to
a limited extent do they support the reflections and actions of the
participants. We propose the use of diaries as a supplement to conventional
methods of reflection on what actually happens and what could happen during the
course of a project, i.e., we propose diaries as a medium for the management of
information systems development projects. This idea is based on an exploratory
study carried out in co-operation with a bank and a research department, and
the idea is supported by theoretical arguments from different fields. In
conclusion, some practical advice on how to use diaries is given together with
some questions for further investigation.

Taskmaster is an interactive environment that employs a unique blend of
graphic technologies and iconic images to support user task specification. In
this environment, problem solving is based on the selection, specification, and
composition of tools that correspond to natural sets of ordered operations.
The Taskmaster environment is novel in that it:

encourages and supports task specification and refinement processes from both
the top-down and bottom-up perspectives; and

enables one to specify parallel tasks in a natural and convenient manner.
To 'program' a given task within the Taskmaster environment, one decomposes it
into an ordered set of conceptually simple, high-level operations, and then
combines (composes) a corresponding network of software tools that implements
these operations. Execution of the specified network provides a task solution.
Major system components supporting user task specification include a network
editor, a tools database and a network execution monitor.

The construction of a graphical presentation involves the representation of
information by means of visual symbols. The acquisition of information from
the resultant graph is a perceptual process that involves the decoding and
interpretation of the visual symbols. Hence good design decisions will be
based on an understanding of the information acquisition process and in
particular graphical perception. This study examines the perception of
bivariate normal data presented in a scatter diagram, and creates a model that
successfully explains how individuals perceive the information contained in
scatterplots.
Subjects were shown a series of scatter diagrams on the CRT of a
microcomputer and were asked to estimate correlation. Several variables were
examined that explain estimated correlation including regression slope,
dispersion, number of points displayed, and the size of the CRT screen. All of
these factors were found to significantly affect subjects' estimates of
correlation.

BIT 1989 Volume 8 Issue 4

We cast the psychology of human-computer interaction (HCI) in terms of task
analysis and the invention of artifacts. We consider the implications of this
for attempts to define HCI in terms of a priori conceptions of psychology. We
suggest that artifacts can be considered theory-like in HCI, and observe that
they do play a theory-like role in the field as practiced. Our proposal
resolves the current methodological perplexity about the legitimacy and
composition of the field. We conclude that HCI is a distinct sort of science:
a design science.

An Analogue and Propositional Hybrid Model for the Perception of Computer
Generated Graphical Images

This research investigated two alternative models, analogue and
propositional, which describe how three-dimensional (3-D) graphical images are
represented and stored in human memory. In order to differentiate between the
two models, three separate experiments were performed using a variation of the
Shepard-Metzler mental rotation paradigm (Shepard and Metzler 1971). For each
experiment, the effects of three independent variables on the performance of a
'mental rotation' task were examined: (a) three levels of figure complexity,
(b) three axes of rotation and (c) four angles of rotation. The subjects' task
was to compare specific angle, axis or depth versus picture plane rotations for
pairs (rotated and non-rotated versions) of 3-D graphic figures displayed on a
CRT. The results indicated that response times varied depending on level of
figure complexity, axis or angle of rotation. A new hybrid model integrating
components of both the analogue and propositional positions is proposed to
explain the reaction time data. In this model, analogue processes occur when
processing requirements for cognitive tasks are low, whereas propositional
processes occur when processing requirements are high. Implications of the
results for the internal representation of 3-D images in human memory and for
the design of graphic work stations are discussed.

Some Uses of the Microcomputer as a Simulation Tool in the Design and
Development of Electronic Visual Display Devices

During the development of displays employing solid-state devices, the need
arises for a technique to assist in the preliminary evaluation of proposed
applications of this fast-moving technology. Some examples are given of
alphameric and graphic displays which may be simulated using a microcomputer.

Statistical Methods for Testing the Conformance of Products to User
Performance Standards

User performance testing is an essential part of the development of
information technology products. Usability engineering techniques and also
methods included in the new International Organization for Standardization
(ISO) draft standard for VDTs involve testing products against a standard or
benchmark. This paper highlights some of the statistical and methodological
problems involved in conformance testing and outlines appropriate procedures.
These include the use of sequential tests which, in comparison with
conventional tests, can achieve a radical reduction in the number of subjects
required.

Developing and Evaluating an Interactive System for Producing Human-Computer
Interfaces

The Author's Interactive Dialogue Environment (AIDE) of the Dialogue
Management System is an integrated set of interactive tools for developing
human-computer interfaces. AIDE is used by an interface specialist, called a
dialogue developer, to implement an interface by directly manipulating and
defining its objects, rather than by the traditional method of writing source
code. This paper describes the structural dialogue transaction model upon
which AIDE is based, describes the use of AIDE for developing human-computer
interfaces, and describes an empirical study comparing use of AIDE with use of
a programming language for implementing a human-computer interface. Results of
this study empirically support, possibly for the first time, the claim that
interactive tools for interface development, such as AIDE, can improve
productivity and reduce frustration in developing interfaces over traditional
programming techniques for interface development.

The Increasing Utility of Incorporating Keywords in Menu Systems as Users
Increase in Experience

The paper begins with a discussion of the problem users experience with
menu-retrieval systems and the possible reasons for their relatively poor
performance. We propose the addition of menu keywords to menu systems to
remedy these problems. Empirical evidence is presented showing that menu
keywords are used increasingly with experience and that retrieval performance
is thereby enhanced substantially.

The increased use of computer technology in most occupations means that many
middle-aged and older workers who lack computer experience will need to acquire
skills to interact with this technology. This study examined age-group
differences in learning to use a text-editing system. One hundred and
thirty-five females ranging in age from 25 to 70 participated in the study.
They received training under one of three training conditions:
instructor-based, online or manual-based. Age differences were assessed by
comparing performance on criterion tasks. Results indicated significant
differences among the groups in learning success, younger learners being the
most successful. There were no significant age by training interactions. The
findings indicate a need to develop more effective training strategies to teach
older learners to use computer technologies. They also indicate the need for
changes in system design because computer applications are difficult for novice
users to learn.

BIT 1989 Volume 8 Issue 5

Towards a Theory of HCI

A framework is described for conceptualizing the interactions between people
and computers which, it is hoped, will provide the basis of a theoretical model
of human-computer interaction (HCI) sufficient to stimulate and guide research
in the field. HCI is viewed as an exchange whose primary purpose is to affect
the states of the agents that are involved. The exchange is ultimately between
people but is partly mediated by artefactual agents acting as intermediaries or
drones of their human owners. A distinction is drawn between interface and
interaction, and the purposes of an interaction in this context are identified
and discussed. In particular, the important purpose of morphogenesis is
further elaborated. On the basis of this, a brief comment is made on what this
implies for the improvement of interactions and then a longer comment is made
on the implications for the separability of front ends. The conclusion is
reached that, even on engineering grounds, the notion of a separate user
interface management system is inherently flawed and that the current trend
towards separable 'interfaces' is an undesirable development.

Computers as Educational Tools

Computerized Tests and Time: Measuring, Limiting and Providing Visual Cues
for Response Time in On-Line Questioning

It is possible and attractive to incorporate time-related measures and
techniques in on-line computerized testing systems. However, is it advisable?
This study focuses on the measurement of response time, the solicitation of
speed, the limitation of allotted time and the provision of on-line visual cues
for the passage of time (on-screen hourglass). An experiment was conducted
using a standard general knowledge component of a psychometric test; 198
students completed an on-line psychometric test under several time-related
experimental conditions. Findings encourage further use of time-related
techniques. Positive correlations were found between performance as measured
by accuracy in response and speed measures. Time-limiting procedures allowed
savings of almost 50% of examinee and examiner's time, without diminishing
score reliability. The reliability of the speed measures is at least as high
as the reliability of accuracy measures. Examinees' stress was not affected,
but intersubjection attitudes are a problem for the incorporation of
time-related measures. Finally, while accuracy scores are biased by
demographics, speed measures seem to be independent of experience in using
computers, gender, age and education.

Learning Studies in the Use of Computer Aided Design Systems for
Discrete-Parts Manufacture

Two-dimensional computer aided engineering design systems are recognized as
having limitations in comparison with the alternative three-dimensional
techniques of solid modelling. The mathematically sounder approach of solid
modelling permits far greater integration between the activities of functional
design, design analysis and manufacturing. However, the existing methods of
specifying design geometry within typical solid modelling systems are deficient
in that they relate more to the mathematical needs of the computer system than
they do to the needs of the designer. CAPE-LUT (Computer Aided Production
Engineering-Loughborough University of Technology) is a prototype system which
provides a machining analogy so that geometric and manufacturing ideas can be
expressed through familiar engineering terminology, to provide detail designs
and outline process plans. CAPE-LUT is an experimental vehicle only and the
system has been used to investigate the hypothesis that a 'manufacturing
features' approach to design and manufacture is easy to learn, accurate and
fast in use, and acceptable to practising designers and manufacturing
engineers. This paper describes the experimental work, which provides
statistical evidence that the manufacturing features method is significantly
easier to learn than a similar CAD system that has a purely geometric
interface. It is also shown that CAPE-LUT performed well when used by
experienced subjects and was acceptable to a large number of practising
engineers.

The Effects of Two- or Three-Dimensional Graphics on the Problem-Solving
Performance of Experienced and Novice Decision Makers

An experiment was performed to investigate the relationship between
two-dimensional (2-D) or three-dimensional (3-D) graphs displayed on paper or
computer and the problem-solving performance of experienced and novice
managers. The effects of these variables on solution times, confidence in
answers and effectiveness of solutions for a production management case were
examined. It was predicted that experienced managers would engage in forward
chaining as a problem-solving strategy, while novices would use backward
chaining as a problem-solving technique (Larkin et al. 1980). Results
indicated that solution times were faster for computer than for paper
presentations of data, but no significant relationship between response times
and dimensionality of graphs was found. Novice subjects produced more accurate
answers using 2-D paper presentations of graphs, while experienced managers
produced more accurate answers when provided with 3-D graphs on computer.
Further, experienced and novice managers were more confident of their answers
when provided 2-D graphs as decision aids than with any other mode of
presentation. Verbal protocols and retrospective reports indicated that in
solving the cases experienced managers engaged in forward chaining, backward
chaining and means-ends analysis as problem-solving techniques more often than
novices.

Impacts on Organizations

Of all organization phenomena and management techniques, the use of
computers and data processing have been perhaps the most distinct and
penetrating. The steady progress of technology and common patterns of growth
have inspired a whole body of literature on the evolution of information
systems. This article reviews the relevant literature and the theoretical
underpinnings of different views. We develop a framework which includes
elements from economics, diffusion theories, organizational learning and growth
and stages theory. Within this framework we integrate different views on the
subject and look at what broader theoretical features are applied in the models
presented in information systems research. On the basis of the review, we draw
some conclusions about the limitations of the models and the need for future
research in the field.

The purpose of this study was to investigate the effects of the format used
to display on-line help (full screen, split screen and windowed) on user
performance and attitudes. Three prototypes of a programmer's editor were
developed. The first prototype provided help in full screen format. The
second prototype provided split screen help and the third windowed help. It
was hypothesized that user performance would be best with windowed help, and
that attitudes would be most positive toward windowed help. In addition it was
believed that windowed help would fare best because it would allow users to see
and work with about two-thirds of the product screen while the help was
displayed. Forty-five application programmers participated. Each subject
performed three editing tasks using one form of on-line help. No significant
differences in performance or attitude were found between those who used full
screen, split screen and windowed help. However, comments made by subjects
during the assessment suggested that the nature of the help text itself may
have affected the results. An examination of these comments indicated several
ways in which the organization and writing style of the help text could be
improved.

The development of different help systems and the application of numerous
approaches to user support have shown (a) that end-users may encounter
insuperably complex use situations, and (b) that it is possible to assist users
significantly by implementing computerized help systems. There are many
approaches to the realization of user support, varying from the use of natural
language to user modelling. However, the current help systems seem to focus on
relatively technical data processing issues, ignoring the organizational
context in which the use takes place. It is asserted in this paper that it is
relevant for users to perceive the organizational context and that it is
possible to reflect the context in a support system. Representing the context
in a support system is made possible by introducing a context database. A
context database is parallel to the actual database and contains information
about task flows, task-connected information objects and the like. Therefore
the analysis of work and information systems has to be based on related areas.
The areas of inquiry are (a) tasks, (b) job design, (c) organization of work,
(d) computer applications and (e) information media. The following kinds of
mappings can be incorporated within the context database: [organizational unit
O1]-[person P1 in job]-[job task T1]-[task-connected information
I1]-[task-connected information I2]-[job task T2]-[person in job
P2]-[organizational unit O2]. This type of chain (or parts of it) can then be
visualized as context support.

Evaluation steered design is an important planning strategy in the
construction of human-computer interfaces (HCI) and survey-based evaluation is
one of the five main evaluation techniques available for use with this
strategy. This paper reports on a survey-based evaluation by questionnaire
that aims at investigating the serviceability and services required for user
recovery and command reuse support. It discusses how to choose an evaluation
method in an evaluation steered design process, analyses the problems of
evaluation by survey, describes the methodology of conducting a mail
questionnaire, reports on the detailed results of this investigation and
provides refinement to the mail questionnaire as a valuable evaluation method
in HCI research. It also proposes topics for further research in this area.

The current paper analyses how human factors aspects and system design
aspects may co-operate in the design of a particular application, i.e.
electronic mail systems. A review of research on the experience of electronic
mail systems is presented, as well as a pilot study covering the experience of
mail systems in different user groups. The users were found to differ mainly
in terms of the tasks they performed and wanted to perform. It is therefore
suggested that a task analysis is essential in system design. Current practice
on task analysis is presented, which shows that a more detailed task analysis
is needed to be useful. In order to achieve flexibility, the subtasks found
should be designed in a modular way. Here the system designer will need
different supports. To facilitate co-operation between end-users and system
designers some kind of communication support is also suggested.

Since the 1970s, many improvements have been made in the technology
available for automatic speech recognition (ASR). Changes in the methods of
analysing the incoming speech have resulted in larger, more complex
vocabularies being used with greater recognition accuracy. Despite this
enhanced performance and substantial research activity, the introduction of
voice input into the office is still largely unrealized. This paper reviews
the state-of-the-art of office applications of ASR, dividing them into the
areas of voice messaging and word processing activities, data entry and
information retrieval systems, and environmental control. Within these areas,
cartographic computer-aided-design systems are identified as an application
with proven success. The slow growth of voice input in the office is discussed
in the light of constraints imposed by existing speech technology, and the need
for human factors evaluation of potential applications.